Abrasive device



OC- 18, 1932- F. o. ALBERTsoN ET AL 1,882,693

ABRASIVE DEVICE Filed Jan. 16, 1931 2 SheetsfSheet l OC- 18, 1932 F.1o. ALBERTsoN ET AL 1,882,593

ABRASIVE DEVICE Filed Jan. 16, 1931 2 Sheets-Sheet 2 Patented oct. 1s, 1932 UNITE-D STATES PATENT OFFICE FRANS 0. ALBERTSON AND GUSTAV A. OLSEN, 0F SIOUX CITY, IOWA, ASSIGNOBS TO ALBERTSON COMPANY, INC., OF SIOUX CITY, IOWA, A CORPORATION `OF IOWA ABRASIVE DEVICE Application led January 16, 1981. Serial No. 509,160.

This invention relates to abrasive devices and more particularly7 to devices adapted for finishing and smoothing operations.

An object of this invention is the provision of an improved abrasive device of the kind above specified which has no metal parts so disposed as to be likely to engage surfaces being polished.

A further object xis the provision of an abrasive device of a simplified construction which is locally yieldable and is adapted to flex at the peripheral margin when suflicient pressure is applied. n

A further object is the provlsion of such a device which is economical to manufacture and which may be simply and quickly assembled and disassembled as for purposes of repair and replacement of parts.

In the accompanying drawings,

Fig. 1 is a rear elevation of my invention taken on the line 1-1 of Fig. 3 and showing the madrel in section;

Fig. 2 is a front elevation of that shown 1n Fig. 1 and with a portion of the abrasive element broken, away;

Fig. 3 is an enlarged section taken substantially on the line 3 3 of'Fig. 15

Fig. 4 is a section taken on the line 4--4 of Fig. 3;

Fig. 5 is a rear elevation of a modified form of my invention;

Fig. 6 is a front elevationof that shown in Fig. 5 and with a portion of the abrasive element broken away; and

Fin'. 7 is an enlarged section taken on the line 5 7 of Fig. 5.

The preferred form of our invention shown in Figs. l to 4 inclusive comprises a hub 1 having a rear flange 2 adapted to engage the face of a mandrel 3. `A fiange 4 on the forward end of the hub is secured to a disc-like support 5 by rivets 6. The peripheral margin 7 of the support 5 is secured rearwardly to provide a seat for the resilient metal backing disc 8 when it is pressed rearwardly by force applied to the abrasive element 9 and transmitted through the flexible disc 10. The disc 10 is preferably composed of rubber in cluding a suitable reinforcing 11 such as fabric vulcanized `to` the rubber and adapted to yield therewith. The disc 10 is provided with a relatively large central aperture and the rear portion of the margin ofjthef'disc about the aperture is cut away to accommodate the peripheral margin of a friction disc 12. The discs 8, 10 and l2 are preferably secured to the support 5 by a plurality of rivets 13, the forward faces 14 of which are countersunk well below the surface of the disc 10 so as not to protrude or engage the abrasive element 9 or surfaces being polished. The abrasive element 9 preferably consists of a preformed and relatively rigid fish paper 15 having suitably secured to the forward surface thereof a multiplicity of emery granules 16.

The central portion of the abrasive element 9 is depressed and passes into the central aperture of the disc 10 and is seated on the rubber face 17 of the friction disc 12. The abrasive element is normally held in this position by means of a relatively wide head 18 on a stud 19, which stud comprises a shank 21 which is internally threaded as indicated at 22 for engagement with threads 23 on the reduced forward portion of the mandrel 3. A portion 24 of the stud shank is preferably non-cylindrical in form and slidably fitted in the similarly formed portion 25 of the hub 1 such that the shank and the hub can not rotate relative to each other whereas rotary movement may be imparted to the stud 19 by reason of its threaded engagement therewith and the same movement may be transmitted from the stud 19 to the hub 1 and from both the stud and the hub to the various disc elements of the abrasive device.

In Figs. 5, 6 and 7 we have illustrated a modification of our invention comprising a hub 31 which has internal threads 32 ada ted to have engagement with a mandrel. he

of Fig. 3 having a central aperture 37 and a recess 38 on its forward face for receiving `the depressed portion 39 of the abrasive element 9. The stud 35 is preferably vprovided with a relatively fiat head 41 which securely '90 hub is also provided with internal threads holds the central portion of the abrasive element 9 in frictional engagement with the reinforcing portion 42 o the disc 36. The head 41 of the stud 35 is preferably provided with a slot 42 into which a suitable tool may be inserted for rotating the head and causing cooperative engagement between the threads 33 and 34 on the hub and stud respectively for holding the abrasive element in position.

In the preferred form of our invention, the stud 19 by reason of its threaded engagement with the mandrel 3 simultaneously and by the same force holds the abrasive element 9 in place and secures the entire assembled device on the end of the mandrel with the flange 2 of the hub engaging the mandrel and thereby transmitting force from the mandrel to the flange 4 of the hub between which and the head 18 of the stud, the various disc-like portions of the device are disposed and securely held while the device as a whole is securely mounted for rotation with the mandrel.

' It will be apparent to those skilled in the art that our device as herein illustrated may be modified without departing from the principle of this invention and we desire to avail ourselves of all such modifications as come Within the scope of the appended claims.

We claim as our invention:

1. In an abrasive device of the class described, a hub, a support on said hub, a. flexible disc secured to said support, said flexible disc having a central aperture, an abrasive facing element on said flexible disc including a depressed portion seated in the aperture of said flexible disc, a stud slidably fitted in said hub, said stud including a flanged head seated on thedepressed portion of said abrasive member, and a threaded por-. tion on said stud adaptedto be secured to the end of a mandrel, a reinforced friction disc fixed to said support and interposed between said support and the depressed portion of said abrasive element to frictionally restrain relative rotary movement of said abrasive element and said support.

2. In an abrasive device of the class described, a hub, ka support on said hub, a flexible disc secured to said support, said flexible disc having a central aperture, an abrasive facing element on said flexible disc including adepressed portion-'seated in the aperture of 4said flexible disc, a stud slidably fitted in said hub, said studincluding a flanged head seated on the depressed portion ofV said abrasive member, a threaded portion on said stud adapted to beksecured to the end of a mandrel, and a spring metal reinforcing backing element interposed between said flexible disc and said support, a reinforced frictiondisc fixed to said support and interposed between said support and the depressed portion of said abrasive element t9 frictionally restrain relative rotary movement of said abrasive element and said support.

3. In a device of the class described, a support comprising a metal disc including a backwardly turned peripheral margin and having a. central aperture, a reinforced friction disc on said support, a reinforced flexible rubber disc havinga central aperture, and mounted on and secured to the marginal portion of said friction disc and to said support, a preformed abrasive facing element on said flexible disc, said abrasive element including a depressed central portion engaging said friction disc, a stud including an internally threaded shank adapted for threaded engagement with a mandrel, and a relatively large head on said stud seated on the depressed portion of said abrasive element for pressing the same against said friction disc, a hub slidably fitted on said stud and including a flange secured to said support.

4. In a device of the class described, a support comprising a metal disc including a backwardly turned peripheral margin and having a central aperture, a reinforced friction disc on said support, a reinforced flexible rubber disc having a central aperture, and mounted on and secured to the marginal portion of said friction disc and to said support, a preformed abrasive facing element on said flexible disc, said abrasive element including a depressed central portion engaging said friction disc, a stud including an internally threaded shank adapted for threaded engagement with a mandrel, and a relal.'

tively large head on said stud seated on the depressed portion of said abrasive element for pressing the same against said friction disc, a hub slidably and non-rotatably fitted on the shank of said stud, and a second flange 'f on said hub adapted to engage a mandrel.

5. In a device of the class described, a support comprising a metal disc including a backwardly turned peripheral margin and having a central aperture, a reinforced friction disc on said support, a reinforced flexible rubber disc having a central aperture, and mounted on and secured to the marginal portion of said friction disc and to said support, a preformed abrasive facing element on said flexible disc, said abrasive element including a'depressed central portion engaging said friction disc, a stud including an internally threaded shank adapted for threaded engagement with a mandrel, and a relatively large head on said stud seated on the depressed portion of said abrasive element for pressing the same against said friction disc, a hub slidably fitted on said stud and including a flange secured to said suppor't, and a resilient `metal reinforcing backing element interposed between said support and said flexible disc and extending beyond the periphery of said support.

6. In an abrasive device, the combination of an arbor having a threadedend with a supporting disc having a hub adapted to be received on said threaded end, a iiexible padV carried by said hub, a facing disc carried by said pad, said hub having a non-circu1ar socket surrounding said arbor and communicating With the face of said pad and disc, and a common securing member for said hub and facing disc comprising a headed member having a threaded bore for receiving the threaded end of said arbor and having an outer surface complementary to the non-circular socket in said hub, whereby said headed member slidably engages in said socket and said headed member may be rotated by means of said pad to thread said headed member home on said arbor and secure said facing disc and hub on said arbor.

7. In an abrasive device, the combination of an arbor having a threaded end with a supporting disc having a hub adapted to be received on said threaded end, a flexible pad carried by said hub, a facing disc carried by said pad, said hub having a non-circular socket surrounding said arbor and communicating With the face of said pad and disc, and a common securing member for sald hub and facing disc comprlsing a head-y ed member having a threaded bore for receiving the threaded end of said arbor and having an outer surface complementary to the non-circular socket in said hub, whereby said headed member slidably engages in said socket and said headed member may be rotated by means of said pad to thread said headed member`home on said arbor and secure said facing disc and hub on said arbor, said arbor havlng an annular shoulder for engaging said hub and said pad and disc havin a depression for receiving the head of sai headed member.

In witness whereof, we hereunto subscribe our names this 5th day of Jan., 1931.

FRANS O. ALBERTSON. GUSTAV A. OLSEN. 

